UNIT 18.17 Fluorescent Peptide Assays for Protein Kinases

  1. Ashwini K. Devkota,
  2. Tamer S. Kaoud,
  3. Mangalika Warthaka,
  4. Kevin N. Dalby

Published Online: 1 JUL 2010

DOI: 10.1002/0471142727.mb1817s91

Current Protocols in Molecular Biology

Current Protocols in Molecular Biology

How to Cite

Devkota, A. K., Kaoud, T. S., Warthaka, M. and Dalby, K. N. 2010. Fluorescent Peptide Assays for Protein Kinases. Current Protocols in Molecular Biology. 91:18.17:18.17.1–18.17.7.

Author Information

  1. University of Texas at Austin, Austin, Texas

Publication History

  1. Published Online: 1 JUL 2010
  2. Published Print: JUL 2010


Protein kinases are enzymes that regulate many cellular events in eukaryotic cells, such as cell-cycle progression, transcription, metabolism, and apoptosis. Protein kinases each have a conserved ATP-binding site, as well as one or more substrate-binding site(s) that exhibit recognition features for a protein substrate. Thus, by bringing ATP and a substrate into close proximity, each protein kinase can modify its substrate by transferring the γ phosphate of the ATP molecule to a serine, threonine, or tyrosine residue on the substrate. In such a way, signaling pathways downstream from the substrate can be regulated, dependent on the phosphorylated versus dephosphorylated forms of the substrate. This unit describes an assay employing a fluorescent peptide substrate to measure the incorporation of non-radiolabeled phosphate. The assay is based on the principle that the phosphorylation of the peptide substrate leads to an increase in the fluorescence emission intensity of an appended fluorophore. Curr. Protoc. Mol. Biol. 91:18.17.1-18.17.7. © 2010 by John Wiley & Sons, Inc.


  • peptide assays;
  • kinases;
  • fluorescent peptides